Furnace for burning pulverized fuel or the like.



No. 638,|6I. Patented Nov. 28, |899. J. B. ARCHER. FURNAGE FUR BURNING `PULVERIZED FUEL 0R THE LIKE.

(Application filed Apr. 8, 1898.) (No Model.) 3 sheets-sheet Patented Nov. 2a, |399. .L B. ARCHER.

FURNACE FUR BURNING PULVERIZED FUEL 0H THE LIKE.

(Application led Apr. 8, 1898.)

(No Model.) 3 Sheets-.Sheet 2.

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N0. 638,|6l. Patented Nov. 28, |899.

J. B. ARCHER.

FURNACE FOR BURNING PULVERIZED FUEL 0R THE LIKE.

(Application filed Apr. B, 1698.)

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F eso l NITED STATES PATENT OFFICE..

JOHN B. ARCHER, OF OAKLAND, CALIFORNIA.

FURNACE FOR BURNING PULVERIZED FUEL OR THE LIKE.

SPECIFICATION forming part of Letters Patent N0. 638,161, dated November 28, 1899. Application filed April 8, 1898. Serial No. 676,945. (No modeld' To all whom t may concern..-

Beit known that I, JOHN B. ARCHER, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in Furnaces for Burning Pulverized Coal or the Like; and I do hereby decl'are the following to be a full, clear, and exact description of said invention, such as willi dicularly under the ame of combustion to lift the same, and in providing the fire-box with leads or entrances to guide a portion of the said supplementary draft to deliver the same tangentially across the iiame of combustion to produce therein a rotary movement.

In the drawings, Figure 1 is a vertical longitudinal section of a boiler provided with a furnace constructed in accordance with this invention. Fig. 2 is a plan view of the furnace, the boiler and its supporting-walls being removed. Fig. 3 is a vertical cross-section of the fire-box or combustion-chamber of the furnace, looking toward the front of the furnace.

The furnace constructed in accordance with this invention and as shown in the drawings consists of a feeding-tube A, the fire-box B, ash-boxes O C, and the two draft-pipes D and E.

The pulverized coal is fed into the tube A. This tube is provided with a spiral conveyer or carrier A'. At the lower end and where it extends into the lire-box B the tube is flattened horizontally to produce a spread delivery end A2. Suitable motive power is connected to the conveyer A', which may be graduated in speed to regulate the feed of the coaldust.

Opening into the flattened portion A2, at the narrow end thereof, is the pipe of the forced draft D. This pipe is connected to any suitable form of blower or air-compressor for the purpose of forcing the air into the fire-box. The air is fed to this blower from asystem of pipes D', in which are formed the loops D2, let into the bottom of the fire-,space under the boiler and to the rear of the fire-box.

The heat generated and maintained in the loops D2 raises thetemperature of the air to be delivered into the attened portion A2 of the feed-pipe. It is the design of the present invention in its perfect working that the air thus introduced should be raised in temperature to about the ignitionpoint of coal. By means of this draft and the preliminary heating of the air the dust as it is fed through the tube A into the iiattened portion A2 is driven horizontally in a sheet over the fire-box B.

The fire-box B is provided at the forward end with a small compartment B', in which a small re is made in the preliminary action of the furnace for the purpose of igniting the combustible material at the beginning of the operation and when the air delivered by the pipe D would not assist in the ignition of the coal-dust. The compartment B' is provided with suitable draft dam per-openings. To the rear of this compartment and covering the entire area of the fire-box is a horizontal partition or floor B2. This floor is constructed of any suitable non-combustible material and supports the perforated cylinders B4. These cylinders are graduated in height from the front upward to the rear, the upper ends of said cylinders being inclined or beveled, forming an approximate straight inclined line from front to rear of the fire-box. The perforations orbores of said cylinders extend through partition or floor B2 and communicate with chamber B2. By means of this arrangement .l the current of air from the forced-air system is given an impetus toward the boiler-casing in an inclined direction.

In the forward end of the chamber B3 extend the draft-pipes E. These are connecte to a system of pipes leading from the abovementioned blower or air-forcing device and an arrangement of coils, loops, or regenerative system by means of which the waste heat is utilized to raise the temperature of the air before entering the chamber B3. The air en- IOO tering the chamber B3 escapes upward into the li re-box -B'throughthe perforated tubes B4.

In the operation of the furnacea portion of the heat generated operates to raise the temperature of these tubes B4, and as the heat is maintained they become heated to a very high degree and raise the temperature of theair passing through them to nearly the same degree as that entering through the pipe D. It is for the purpose of retaining and adding to this heat that the Hoor of the partition dividing the fire-box B and chamber B3 is spread with a masticated material consisting of broken slag or fire-brick. By means of the two drafts entering by the pipe D and the pipe E, the latter being directed on a plane perpendicular to that of the former, the effeet in the operation of the furnace is to throw the sheet of ignited material out over the rebox in the one instance and to raise it upward against the bottom of the boiler in the other instance.

The fire-box Bis surrounded by an air-space B5, which communicates with the fire-box B through small perforations B6 in the side walls of the fire-box. The perforations B6 are located near the top of the fire-box and are extended horizontally through the side walls of the same in an oblique direction. The draft driving through the perforations B6 will prod-uee a rotation of the atmosphere within the fire-box. This revolves the ignited material, and the whole volu me of ignited material is given a'rapid rotary movement within the firebox as it leaves the same to pass through the fire-.space under the boiler.

The perforations B6,formed in the side walls,

Ymay be substituted for by pipes suitably ar-` ranged to deliver the draft into the furnace tangentially, and thus produce the rotary movement in the same manner as described with regard to the perforations.

The side walls of the fire-box, through which the perforations B6 extend, are constructed of fire-brick set at an angle to the face of the wall. They are also preferably provided on the en ds which extend into theV fire-box with conical projections B7. These projections B7 become intensely heated and serve to increase the heat of the combustion within the tire-box. The masticated material, which is placed on the iloor between the fire-box and chamber B3, is also formed to present a number of sharp angles or edges, which likewise become intensely heated.

As the anle is carried through the firespace under the boiler it heats the loops D2 of the forced-draft system and heats the air passing through the loops before it is introduced into the contracted end A2 of the feedpipe A. The forced-draft systems D and E are both connected to the same blower.

By means of the construction herein described the combustion of the coal is perfect and no smoke is produced, even when soft or bituminous coals are used. Further, the sooty depositsincident to slow or poor combustion are avoided, making the use of the invention desired in all classes of furnaces.

lVhile the drawings show and this specification describes the invention as applied to a horizontal boiler of ordinary construction, it will be understood that it may be applied to any ofthe known types, such as locomotive or vertical boilers. Also it may be applied to reheatin'g furnaces for iron, steel, or other materials by altering the construction to suit the conditions.

Having thus described this invention, what is claimed is- 1. The herein-described furnace, comprising a fire-box having its side walls provided with a series of horizontal,obliquely-arranged f perforations, a series of cylindrical'projections supported in said fire-box and graduated in height from the front upward to the rear of said fire-box said projections being provided with longitudinal bores, means for introducing fuel to said fire-box in a powdered or pulverized state, and means for forcing a current of air simultaneously through said obliquely-arran ged perforations and the bores of said projections, substantially as set forth.

2. The herein-described furnace, comprising' a casing having an air space or chamber, a {ire-box located therein, the walls of'said fire-box beingprovided with a series of 'horizontal obliquely-'arran ged perfo rations, a horizontal plate extending across said space,form ing a lower-chamber, a series of cylindrical projections supported by said plate and having longitudinal bores communicating with said chamber, said projections being graduated in' height from the front upward to the rear of said fire-box, means for feeding coal to said fire-box when in powdered state, and means for forcing a current of air simultaneously through said feeding means andthe said air-space and lower: chamber, substantially as set forth.

3. The hereindescribed furnace, comprisinga lire-box having its walls provided with a series of horizontal obliquely-arranged perforations, the inner faces of said walls being provided with conical project-ions, a series of vertically-arran ged projections located in said fire-box` and having longitudinal bores, said latter projections beingV graduated in height from the front upward to the rear of said ire'- boX and having their ends beveled in the same direction, means for feeding coal to said fire-box when in a powdered state, and means for forcing a current of air simultaneously through said obliquely-arranged perforations and the bores of said vertical projections, substantially as set forth.

4f. The herein-described furnace, compris- IOO r F i i i i ro air-inlet pipe leading into said air-chamber,

branch pipes leading from said latter pipe to said air-space, and means for forcing air through all of said pipes; substantially as described.

In testimony whereof I have hereunto set I5 my hand this 1st day of April, 1898.

JOHN B. ARCHER. Vitnesses:

E. F. MURDOCK, MAYNARD HAINES. 

